The use of chlorine to sanitize freshly harvested produce (i.e. fruits and vegetables) has been well-described. Generally, chlorine is added to water as a gas to produce hypochlorite which is the active sanitizing agent. A use level of about 100 ppm has been previously described as efficacious in reducing microbial counts and being effective against pathogens. Use levels can fluctuate as a function of soil and dirt load as well as microbial contamination levels. However, the use of chlorine presents several issues to both the production operation as well as the consumer. One shortfall of chlorine is that it is a toxic gas, which is monitored by Homeland Security, thereby complicating its handling and use. Because chlorine is toxic, accidental release can be dangerous to humans and animals. Chlorine can react with organic compounds to produce low levels of chloroform, a known carcinogen and EPA-monitored effluent contaminant. While it can be an effective sanitizing agent, chlorine is not as effective as a de-soiling agent.
It would be advantageous to identify a method for de-soiling and disinfecting produce that avoids or mitigates the toxic concerns of chlorine gas that provides significant de-soiling properties, possesses sanitation capabilities equal to or greater than chlorination, produces safe products, and can be disposed of without concern for contamination. One such method involves using the products of water electrolysis.
The electrochemistry of water was described centuries ago in the work of Sir Humphrey Davey, and in the 1837 publication of Michael Faraday entitled “The Laws of Electrolysis.” Recent advances in metal and ceramic sciences has enabled the electrolysis of water to be selectively controlled, and can result in the production of two end-products, each with their own unique properties. The cathode produces a solution known as catholyte, which possesses unique de-soiling properties. The anode produces a product known as anolyte, which has been shown to have strong sanitizing qualities.
US Patent Application Publication No. 2005-0244556 A1 describes a method of de-soiling meat and hide products by saponifying the meat or hide with electrolyzed alkaline water, and disinfecting the meat or hide by treating with electrolyzed acidic water. However, one disadvantage of this method is that the electrolyzed acidic solutions have low pH's, which could damage the soft surfaces of fruits and vegetables. Furthermore, the electrolytic cell used produces turbulent flow through plate-type exchangers, which does not result in optimal salt conversion rates.
Therefore there is a need to develop a method of de-soiling and disinfecting soft surfaces, such as those of fruits and vegetables, that optimizes water electrolysis and utilizes an anolyte solution with a neutral pH. Furthermore, it would be advantageous to combine the unique de-soiling properties of the catholyte with sonication to enhance the de-soiling of produce prior to disinfecting. The value of such a non-toxic method could have a significant impact on reducing not only bacterial load but also reducing the pathogenic loads that have been most recently described as resulting in food-borne illness.